habanalabs: support temperature offset via sysfs

This commit adds support for offsetting the temperatures reading
by a specified value as defined in
https://www.kernel.org/doc/Documentation/hwmon/sysfs-interface
using the standard sysfs defined for hwmon.
This is required by system administrators to inject errors to test
their monitoring applications in data centers.
Signed-off-by: Moti Haimovski <mhaimovski@habana.ai>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

drivers/misc/habanalabs/habanalabs.h

@@ -1610,6 +1610,8 @@ int hl_pci_set_dma_mask(struct hl_device *hdev, u8 dma_mask);
 long hl_get_frequency(struct hl_device *hdev, u32 pll_index, bool curr);
 void hl_set_frequency(struct hl_device *hdev, u32 pll_index, u64 freq);
 long hl_get_temperature(struct hl_device *hdev, int sensor_index, u32 attr);
+int hl_set_temperature(struct hl_device *hdev,
+			int sensor_index, u32 attr, long value);
 long hl_get_voltage(struct hl_device *hdev, int sensor_index, u32 attr);
 long hl_get_current(struct hl_device *hdev, int sensor_index, u32 attr);
 long hl_get_fan_speed(struct hl_device *hdev, int sensor_index, u32 attr);

drivers/misc/habanalabs/hwmon.c

@@ -125,6 +125,7 @@ static int hl_read(struct device *dev, enum hwmon_sensor_types type,
 		case hwmon_temp_crit:
 		case hwmon_temp_max_hyst:
 		case hwmon_temp_crit_hyst:
+		case hwmon_temp_offset:
 			break;
 		default:
 			return -EINVAL;
@@ -192,6 +193,15 @@ static int hl_write(struct device *dev, enum hwmon_sensor_types type,
 		return -ENODEV;
 
 	switch (type) {
+	case hwmon_temp:
+		switch (attr) {
+		case hwmon_temp_offset:
+			break;
+		default:
+			return -EINVAL;
+		}
+		hl_set_temperature(hdev, channel, attr, val);
+		break;
 	case hwmon_pwm:
 		switch (attr) {
 		case hwmon_pwm_input:
@@ -220,6 +230,8 @@ static umode_t hl_is_visible(const void *data, enum hwmon_sensor_types type,
 		case hwmon_temp_crit:
 		case hwmon_temp_crit_hyst:
 			return 0444;
+		case hwmon_temp_offset:
+			return 0644;
 		}
 		break;
 	case hwmon_in:
@@ -291,6 +303,31 @@ long hl_get_temperature(struct hl_device *hdev, int sensor_index, u32 attr)
 	return result;
 }
 
+int hl_set_temperature(struct hl_device *hdev,
+			int sensor_index, u32 attr, long value)
+{
+	struct armcp_packet pkt;
+	int rc;
+
+	memset(&pkt, 0, sizeof(pkt));
+
+	pkt.ctl = cpu_to_le32(ARMCP_PACKET_TEMPERATURE_SET <<
+				ARMCP_PKT_CTL_OPCODE_SHIFT);
+	pkt.sensor_index = __cpu_to_le16(sensor_index);
+	pkt.type = __cpu_to_le16(attr);
+	pkt.value = __cpu_to_le64(value);
+
+	rc = hdev->asic_funcs->send_cpu_message(hdev, (u32 *) &pkt, sizeof(pkt),
+						SENSORS_PKT_TIMEOUT, NULL);
+
+	if (rc)
+		dev_err(hdev->dev,
+			"Failed to set temperature of sensor %d, error %d\n",
+			sensor_index, rc);
+
+	return rc;
+}
+
 long hl_get_voltage(struct hl_device *hdev, int sensor_index, u32 attr)
 {
 	struct armcp_packet pkt;

drivers/misc/habanalabs/include/armcp_if.h

@@ -189,6 +189,10 @@ enum pq_init_status {
  *       ArmCP to write to the structure, to prevent data corruption in case of
  *       mismatched driver/FW versions.
  *
+ * ARMCP_PACKET_TEMPERATURE_SET -
+ *       Set the value of the offset property of a specified thermal sensor.
+ *       The packet's arguments specify the desired sensor and the field to
+ *       set.
  */
 
 enum armcp_packet_id {
@@ -214,6 +218,8 @@ enum armcp_packet_id {
 	ARMCP_PACKET_MAX_POWER_GET,		/* sysfs */
 	ARMCP_PACKET_MAX_POWER_SET,		/* sysfs */
 	ARMCP_PACKET_EEPROM_DATA_GET,		/* sysfs */
+	ARMCP_RESERVED,
+	ARMCP_PACKET_TEMPERATURE_SET,		/* sysfs */
 };
 
 #define ARMCP_PACKET_FENCE_VAL	0xFE8CE7A5
@@ -271,12 +277,17 @@ enum armcp_packet_rc {
 	armcp_packet_fault
 };
 
+/*
+ * armcp_temp_type should adhere to hwmon_temp_attributes
+ * defined in Linux kernel hwmon.h file
+ */
 enum armcp_temp_type {
 	armcp_temp_input,
 	armcp_temp_max = 6,
 	armcp_temp_max_hyst,
 	armcp_temp_crit,
-	armcp_temp_crit_hyst
+	armcp_temp_crit_hyst,
+	armcp_temp_offset = 19
 };
 
 enum armcp_in_attributes {